Luminescent and magnetic properties of two novel coordination polymers based on N-heterocyclic carboxylic acid

A new Cu(II)-containing coordination polymer: protective effect and mechanism exploration on elderly osteoporotic hip fractures via regulating the wnt signaling pathway

Elderly osteoporosis hip fracture has drawn the attention of the researcher. The coordination polymer was now widely used in clinic because their multiple structures and biological activities. In this present research, the new coordination polymer was designed and synthesized and their application values on elderly osteoporosis hip were evaluated. The reaction between Cu(II) salt and 4,4'-(1H-1,2,4-triazol-1-yl)methylene-bis(benzoic acid) (H2tzmb), an aromatase inhibitor letrozole derivative with the aid of the organic linker 4,4-bipyridine (4,4'-bpy) affords a new coordination polymer based on Cu(II) ions as nodes of {[Cu2(tzmb)2(4,4'-bpy) (μ2-H2O)2(DMA) (H2O)2]·10DMA}n (1). The complex 1 gained is totally investigated with the powder X-ray diffraction study, thermogravimetric analyses, the diffraction of single-crystal X-ray, elemental analysis as well as the Fourier transform infrared spectrometer spectra. The osteogenic differentiation of mesenchymal stem cell was measured with the western blotting assay through determining the Runx2 expression. The wnt signaling pathway relative expression in mesenchymal stem cell was detected through the determination of real-time RT-PCR. The cytotoxicity of the compound on the mesenchymal stem cell was determined with CCK-8 assay. The result of single-crystal X-ray diffraction reflects that the complex 1 has crystallized in space group R-3c of trigonal system and exhibits a three-dimensional skeleton architecture on the bases of the SBUs {Cu(tzmb)(μ2-H2O)}n. The western blotting assay results revealed that this compound could significantly promote the osteogenic differentiation of mesenchymal stem cell. Besides, the activation of wnt signaling pathway in mesenchymal stem cell was also increased by the compound exposure. Finally, it can be summed up that this compound has excellent application values on the elderly osteoporotic hip fractures treatment by increasing the activation of wnt signaling pathway in mesenchymal stem cell. The results of the CCK-8 assay indicated that the compound has no cytotoxicity on the mesenchymal stem cell. The molecular docking simulation results have identified that only the carboxyl group on the Cu complex exhibits the activity for the hydrogen bond formation, however, the pyridine ring does not have such activity, instead, the pyridine ring only acts as the ligand that binds to the Cu ion. This Cu(II) coordination polymer has excellent application values on the elderly osteoporotic hip fractures treatment by increasing the activation of wnt signaling pathway in mesenchymal stem cell.

A new luminescent metal-organic framework with 2,6-di(1H-imidazol-1-yl)naphthalene and biphenyl-3,4′,5-tricarboxylic acid

In this work, a novel metal-organic framework (MOF) based on 2,6-di(1H-imidazol-1-yl)naphthalene (L) and biphenyl-3,4′,5-tricarboxylic acid (H3bptc), namely [Co(L)(Hbptc)(H2O)] (1), has been prepared. 1 has a distinct infinite chain structure, further linked together by winding interactions to give the three-dimensional (3D) network structure. 1 was characterized by X-ray crystallography, infrared spectra (IR) spectroscopy, elemental and thermal analysis. Photoluminescence studies revealed that 1 shows a strong emission at 361 nm upon excitation at 290 nm at room temperature. Moreover, 1 can efficiently detect Fe3+ ions by luminescence quenching.

Coordination Polymers Based on Highly Emissive Ligands: Synthesis and Functional Properties

Coordination polymers are constructed from metal ions and bridging ligands, linking them into solid-state structures extending in one (1D), two (2D) or three dimensions (3D). Two- and three-dimensional coordination polymers with potential voids are often referred to as metal-organic frameworks (MOFs) or porous coordination polymers. Luminescence is an important property of coordination polymers, often playing a key role in their applications. Photophysical properties of the coordination polymers can be associated with intraligand, metal-centered, guest-centered, metal-to-ligand and ligand-to-metal electron transitions. In recent years, a rapid growth of publications devoted to luminescent or fluorescent coordination polymers can be observed. In this review the use of fluorescent ligands, namely, 4,4'-stilbenedicarboxylic acid, 1,3,4-oxadiazole, thiazole, 2,1,3-benzothiadiazole, terpyridine and carbazole derivatives, naphthalene diimides, 4,4',4''-nitrilotribenzoic acid, ruthenium(II) and iridium(III) complexes, boron-dipyrromethene (BODIPY) derivatives, porphyrins, for the construction of coordination polymers are surveyed. Applications of such coordination polymers based on their photophysical properties will be discussed. The review covers the literature published before April 2020.